Electrical alarm for thermostats



oct. 15, 1929. H, PIQ'UT 1,731,937

ELECTRICAL ALARM FOR THERMOSTATS Henri Pique 1L Oct. 15, 1929. H. PIQUET 1,731,937

I ELECTRICAL ALARM FOR THERlIOSTATS Filed Aug. 15, 192'? 2 sheets-sheet 2 ZZ l I i /Zq jme/wm Henri PfgL/e 4M fm. www..

Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE HENRI PIGUET, OF JACKSONVILLE, FLORIDA, ASSIGNOR OF ONE-HALF TO FRED PERCI- VAL JONES, OF GRAND CROSSING, FLORIDA ELECTRICAL ALARM FOR THERMOSTATS Application filed August 15, 1927.

This invention comprises an improved electrical alarm for thermostats and has for one object to provide a device of this character which may be attached to a conventional type of incubator to co-operate with the damper regulating lever thereof and adapted to sound at predetermined maximum and minimum temperatures within the incubator.

Another object is to provide a device ot this character employing a contact carrying member having movable contact members mounted in spaced relation thereon and adapted to selectively co-operate with the damper regulating lever of the incubator for sounding the 'alarm and wherein the said contact carrying member will be bodily movable to simultaneously adjust the said contact members relative to the said lever for regulating the instant ot contact therebetween.

Another object is to provide a device of this character wherein each of the said contact members may be independently adjusted upon the contact carrying member and thus further regulate the instant of contact between the damper regulating lever and t-he said Contact members.

Another object of my invention is to provide said movable contacts in a form adapted to yieldingly engage said damper regulating lever so as to permit said lever to have its lull amplitude of movement irrespective of the setting of the said contact members relative to said lever, thereby favoring the precise and prompt regulation of the temperature within the said incubator.

lVith the above and other objects in view, my invention consists in the combination and arrangement or" parts hereinafter described and claimed, and more particularly illustrated in the accompanying drawings, wherein Figure 1 is a front elevation of my improved alarm showing the device applied to a conventional type ot incubator, the body Serial N0. 212,987.

of which is shown in section, and a diagrammatic alarm operating circuit being shown in connection with the device.

Figure 2 is a sectional end view along the line 2 2 of Figure 1, the damper being removed.

Figure 3 Figure 1.

Figure 4 is a view along the line 4 4 of Figure 1, showing the contact carrying arm with the movable contact members mounted thereon, the damper regulating lever being shown as raised and engaging the upper of said Contact members.

Figure 5 is a detail of one of the contact members.

Figure 6 is a sectional view along the line 6-6 of Figure 1.

Referring now more particularly to the drawings, I show a conventional type of incubator 10, having a bracket 1 upon which is pivotally mounted a damper regulating lcver 1l, which in the embodiment shown is made of conductive material, and which is controlled by a thermostat 12 through a rod 2 in the usual manner, and is provided, at its free extremity, with a damper rod 3 pivotally connected to a damper lever Ll, pivoted at one end to a bracket 5 on the incubator wall, and having its other end engaged with a plunger 6 depending from a damper 13 adapted to fit over the upper end of the lamp flue 14, so that, as the said damper is raised from said flue, the incubator will be ventilated and cooled, and as the damper is lowered to said flue, the incubator will be warmed. The thermostat 12 is supported interiorly the incubator 10 by a bracket 7 (Figure 1).

In carrying out my invention, I employ a bracket 15 adjustably mounted on the incubator 10 as by screws 16 engaging slotted holes 17 provided in the right angularly eX- tending flange 18 ot' said bracket. Similar slotted holes 17 are also provided in the is a fragmentary plan view of body of the bracket adjacent to said flange, whereby said bracket may be mounted in any convenient manner on said incubator. lThe said bracket 15 terminates in spaced and parallel fingers 19, and each of said iingers has a longitudinally extending slot 20; outstanding tlanges 21 are provided on each tin-- ger spaced trom and parallel to said slot 2O.V

In the embodiment shown, the bracket 15 is mounted so as to have the tingers 19 extending vertically.

A base 22, constructed of conductive material, is adjustably mounted on the bracket 15 as by bolts 23 passing through apertures 32 in said base and extending through said slots 20; the nuts 2st of said bolts engage the flanges 21 and are thus prevented from turning when said bolts are tightened. By this means the base 22 may be adj usted on the incubator so as toproperly position the contacts Si@ and 34h hereinafter described relatively to the regulating` arm 11. 1n the embodiment shown, the base 22 extends horizontally, but if desired the said base may extend vertically, and an aperture 32 is provided in the basey 22 for this purpose.

A bolt 25 is mounted through a block oi insulating material 9 which is mounted on the base 22, and the bolt 25 is conductively connected toa switch 26 also mounted on said insulating block 9. The bolt 25 and switch 26 are thus insulated from the base 22. rihe head of the bolt is spaced from the block 9 by ametal. sleeve 25- on which is slidably mounted a slotted bar 27 of conductive material pivot-ally engaging a conductive bracket 28 adjustably mounted on the damper regulating lever 11. By the means described, the said lever 11 is conductively connected to the said switch 26 through the sleeve 25a and the bolt 25.

A contact carrying arm S is mounted on said base 224 and. extends right angularly thereto. Aligned upper and lower slotted holes 29 are provided in said arm S, and an outstanding flange 30 is provided on said arm spaced from and parallel to said slotted holes29. Pins 31 slidably engage said slotted holes 29, and each pin threadedly engages a nut 33, tor the purpose ot positioning said pin in said slotted hole. The flange 30 prevents the turning of saidnut 33-when said pin 31 is rotated, as by its knurled head 31a, tor the purpose of securing said pin in said slotted hole 29 and thus to said arm 8.

L-sliaped movable Contact members 3er-1 and 34h are spaced above and below said lever 11, respectively, and each comprises a single piece ot conductive material having a contact tinger 35 bent right angularly from the body ot said member, and, also, spaced upstanding ears 36 are termed medially ot the body of said member and extend in a direction oppositely to said finger The said ears 3G have aligned apertures 37 whereby said contact member may be ournaled on the pin 31. By the means described, the said contact members may be adj ustably positioned and secured on said contact carrying arm 8 relative ly to the normal operating position ot the lever 11.

riihe end -12 oi each oi said contact members oppositelyoi' said linger 35 is adapted to engage screws 38a and 38h, each threadedly engaging brackets 39 extending from the base 22 above and below said lever 11, respectively. A slotted aperture e() is provided in said base 22 and the lever 11 is passed freely therethrough, the length of said slotted aperture bei sufficient to permit said lever 11 to have its tull amplitude ot movement in regulating the temperature within said incubator whereby said lever is thus airinsulated from the base 22. 1n the embodiment shown the said slotted aperture 4Q is formed by striking out said brackets from the material. ot said base, the brackets thus being positioned at the top and bottom ot said aperture.

rilhe iower cont-act member 3@ is provided with a counter-weight L t1 on the end 12 thereot, for the purpose oi keeping said end normally n eiigagement with the set screw 38h, whit iu this case extends upwardly from its bracket rEhe weight ot the contact nger 35 o'r the upper contact member 34a will keep the end 42 ogt said contact member in engagement with the set screw 38a, which in this case Y extends downwardly from its bracket 39. By

suitably adjusting the set screws 38a and 38h the ends 42 ot' the contact members may be raised or lowered so as to cause the said contact fingers 35 to take any desired relation with respect to the lever 11.

sin electrical terminal 113 is mounted on the base 22, and detachably connected thereto is a wire 4e which leads to a battery L18' or other suitable conveniently located source ot electrical energy. Leading from the battery is a wire which is connected to one terminal of a. suitable alarm L16, and leading from the other terminal of the alarm is a wire t? which is detachably connected to the switch terminal 25a mounted on and conductively connected to the switch 26.

in use, the switch 26 being closed, the movement ot the-damper regulating lever 11 is controlled by the thermostat 12 through the rod 2, and it wili be seen that when the tree extremity ot said lever is moved upwardly to actuate the damper 13, through the rod 3 and lever 4, to ventilato the incubator so as to reduce the temperature therein, the said lever is adapted to engage the Contact finger 35 the upper contact member 311:1, thereby establishing an electrical circuit so that current will flow trom the battery through the wire 45 to the alarm e6, thence through the wire 47 to the terminal 2ta and switch 26 and thru the bolt 2'", sleeve 25a, slotted bar 27, bracket 28, lever 11, Contact ea, base 22, terminal Li3 and wire del to the battery. Consequently', the aiarm will be automatically sounded at s ch time as the temperature of the incubat r reaches a maximum suiiicient to cause the i n lativg lever to be raised to a predetermined poi t. But, b y the construction ci the conbct member 84a, as described, the upwar l movement of the lever ll is not ed by the engagement tliereoi1 with said g ii conditions require the same, said lever il may be urther moved upwardly by the thermostat l2, wl ereupon the contact 3 will yieldin engage said lever il id contact mcmoer rotating about the pin 8l, thus permiloting,l the further upward movement of said lever. litter the lever has ieen so riised and the temperature within the incubator is reduced, the free extremity of the namper regulating lever will be lowered as lo move toward the flue la to close the same by means of the damper 13, and is adapted to engage the lower contact member Sb. ,Current will then flow, as before described, except that the contact member Se? will now serve as the conductive medium between the baie Q2 and the lever ll. The level' ll, aiter engaging the contact 31th, may be further moved downwardly by the thermostat l2; the contact finger 35 will yieldingly engage the lever ll as by the contact member JA rotating on the lower pin 3l, thus permitting the further downward movement ot the lever.

Consequently, the alarm 46 will be automatically sounded whenever the lever l1 is moved by means of the thermostat l2 a predetermined distance. Thus, Jfor example, the upper contact member 34 and, consequently, the contact finger 35 thereon, may be adjusted on the contact carrying arm 8 so that as said lever ll is moved upwardly by said thermostat, the said contact finger 35 oit' said Contact member will engage the said lever 11 when he temperature within the incubator is, for example, 104: degrees, whereupon the electrical circuit will be closed and the alarm will be sounded, but the lever 1l, if necessary, may further rise, as described, so as to quickly bring the temperature of the incubator to normal. Conversely, the lower contact member 34h and, consequently, the contact linger 35 thereon, may be adjusted on the contact carrying arm 8 so that as said lever l1 is moved downwardly by said thermostat, the said contact finger 85 of said contact member will encage said lever l1 when the tempe ature within the incubator is, for example, 101 degrees, whereupon the electrical circuit will be closed and the alarm will be sounded, but the lever 1l, if necessary, may be caused to have a further downward movement, as described, so as to quickly bring the temperature of the incubator to normal. It will be seen, therefore, that by my construction, an alarm is sounded as soon as the temperature within the incubator departs from the safe limits of temperature range of operation thereof, while at the same time, the thermostat is permitted to freely operate the damper in the usual manner, so as to promptly and with out hindrance, bring` the temperature within the incubator to its proper point.

In the embodiment shown, the base 22 may be vertically adjusted relative to the incubator so as to simultaneously adjust the instant of contact between the regulating lever 11 and each of the contacts Si and 84h, for controlling the soundingr of the alarm at various predetermined maximum and minimum temperatures within the incubator, but preferably the permissible range of temperatures will be determined by adjusting the set screws 38aL and 38h for maximum and minimum temperatures, respectively. When it is desired to render the alarm inoperative, it is only necessary to open the switch 26, without disturbing the setting of the device in any manner.

IVhile I have herein shown and described my invention in connection with a thermostatically controlled incubator, I do not wish to be limited to the precise construction shown in the employment of my invention. It will be readily seen that my invention consists of a device which may be used with any thermostatically controlled device, such as ventilators or valves for letting heat in or out of a chamber or room, such as for drying` ovens, and the like. My invention is also adapted for use with a thermostat for various purposes generally so as to `give an alarm whenever the temperature rises or falls to a predetermined point, such as, for example, a fire alarm for a home or buildings, the existence of a tire serving to cause the thermostat to operate the alarm, in a manner similar to that described. It will be seen that, if desired, the thermostat may be enclosed in a heat resisting cabinet so that the alarm would only be sounded when the heat was sufficient to overcome the resistance ot the cabinet and thus operate the thermostat. Other uses of my invention will be readily apparent to those skilled in the art.

IVhile I have herein described a certain specilic manner and method of constructing and assembling the elements of my invention, it is understood that I may vary from the same in minor details, not departing from the spirit of my invention, so as best to construct a practical device for the purpose intended, as defined in the appended claim.

I claim:

The combination with an alarm circuit of an oscillatingr lever ot' conductive material, of a base of conductive material, a conductive bolt insulatably mounted on said base, a conductive bar slidably engaging` said bolt, a conductive bracket adjustably mounted on said lever and pivotally engaging said bar, a conductive contact member adjustably mounted on said base for rotation in the plane of oscillation of saicl lever, a finger formed on said Contact member adapted to operatively engage the said lever for the rotation of said Contact, and means for acljustably spacing said finger with respect to the normal operating position of said lever, said linger orm ing one of the terminals of said alarm circuit, and said lever forming the other of said terminals.

In testimony whereof I aiX my signature.

' HENRI PIQUET. 

